Method and System for Double-Sided Patterning of Substrates

ABSTRACT

The present invention is directed towards a method and a system of patterning first and second opposed sides of a substrate. The method and system may employ a mold assembly and obtaining a desired spatial relationship between the first and second opposed sides of the substrate and the mold assembly. In a further embodiment, the method and system may employ a first and a second mold assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional ApplicationNo. 60/748,430, filed on Dec. 8, 2005, entitled “Apparatus for andMethods for Imprinting, Aligning, and Separation for Double SideImprinting,” the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

The field of the invention relates generally to nano-fabrication ofstructures. More particularly, the present invention is directed to amethod and a system of double-sided patterning of a substrate.

BACKGROUND INFORMATION

Nano-fabrication involves the fabrication of very small structures,e.g., having features on the order of nanometers or smaller. One area inwhich nano-fabrication has had a sizeable impact is in the processing ofintegrated circuits. As the semiconductor processing industry continuesto strive for larger production yields while increasing the circuits perunit area formed on a substrate, nano-fabrication becomes increasinglyimportant. Nano-fabrication provides greater process control whileallowing increased reduction of the minimum feature dimension of thestructures formed. Other areas of development in which nano-fabricationhas been employed include biotechnology, optical technology, mechanicalsystems and the like.

An exemplary nano-fabrication technique is commonly referred to asimprint lithography. Exemplary imprint lithography processes aredescribed in detail in numerous publications, such as United Statespatent application publication 2004/0065976 filed as U.S. patentapplication Ser. No. 10/264,960, entitled, “Method and a Mold to ArrangeFeatures on a Substrate to Replicate Features having Minimal DimensionalVariability”; United States patent application publication 2004/0065252filed as U.S. patent application Ser. No. 10/264,926, entitled “Methodof Forming a Layer on a Substrate to Facilitate Fabrication of MetrologyStandards”; and U.S. Pat. No. 6,936,194, entitled “Functional PatterningMaterial for Imprint Lithography Processes,” all of which are assignedto the assignee of the present invention.

The imprint lithography technique disclosed in each of theaforementioned United States patent application publications and UnitedStates patent includes formation of a relief pattern in a polymerizablelayer and transferring a pattern corresponding to the relief patterninto an underlying substrate. The substrate may be positioned upon amotion stage to obtain a desired position to facilitate patterningthereof. To that end, a template is employed spaced-apart from thesubstrate with a formable liquid present between the template and thesubstrate. The liquid is solidified to form a solidified layer that hasa pattern recorded therein that is conforming to a shape of the surfaceof the template in contact with the liquid. The template is thenseparated from the solidified layer such that the template and thesubstrate are spaced-apart. The substrate and the solidified layer arethen subjected to processes to transfer, into the substrate, a reliefimage that corresponds to the pattern in the solidified layer.

In some applications, it may be desirable to form a relief pattern onfirst and second opposed sides of the substrate. Forming a pattern onfirst and second opposed sides of the substrate, i.e. double-sidedpatterning, may be beneficial in the area of patterned media imprinting.To that end, a need therefore exists to provide a method and a system ofdouble-sided patterning of substrates.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified side view of a lithographic system having atemplate spaced-apart from a substrate, the substrate having first andsecond opposed sides;

FIG. 2 is a top down view of the template shown in FIG. 1;

FIG. 3 is a side view of the template shown in FIG. 1;

FIG. 4 is an exploded view of a portion of FIG. 2, the template havingan alignment mark;

FIG. 5 is a side view of the substrate shown in FIG. 1, and an opticaldetection system for detecting the substrate;

FIG. 6 is a top down view of the substrate shown in FIG. 1, and anoptical detection system for detecting the substrate;

FIG. 7 is a top down view of a robot handling the substrate shown inFIG. 1;

FIG. 8 is a flow diagram showing a method of patterning the first andsecond opposed sides of the substrate shown in FIG. 1, in a firstembodiment;

FIG. 9 is a side view of the system shown in FIG. 1, with a robotpositioning the substrate on a substrate chuck in a first position;

FIG. 10 is a side view of the system shown in FIG. 9, with the substratehaving a material positioned on a first side thereof;

FIG. 11 is a side view of the system shown in FIG. 10, with the templatecontacting the fluid positioned on the first side of the substrate;

FIG. 12 is a side view of the system shown in FIG. 11, with the robotpositioning the substrate on the substrate chuck in a second position;

FIG. 13 is a side view of the system shown in FIG. 12, with the templatecontacting a fluid positioned on the second side of the substrate;

FIG. 14 is a side view of a lithographic system having a first templateopposed a second template and a substrate, the substrate having firstand second opposed sides, in a further embodiment;

FIG. 15 is a flow diagram showing a method of patterning the first andsecond opposed sides of the substrate shown in FIG. 14, in a furtherembodiment;

FIG. 16 is a side view of the system shown in FIG. 14, with a robotpositioning the substrate on a substrate chuck in a first position;

FIG. 17 is a side view of the system shown in FIG. 16, with thesubstrate having a material positioned on the first side thereof;

FIG. 18 is a side view of the system shown in FIG. 17, with the firsttemplate contacting the fluid positioned on the first side of thesubstrate;

FIG. 19 is a side view of the system shown in FIG. 18, with thesubstrate being coupled to the first template and the substrate having amaterial positioned on the second side thereof;

FIG. 20 is a side view of the system shown in FIG. 19, with the secondtemplate contacting the fluid positioned on the second side of thesubstrate;

FIG. 21 is a side view of the system shown in FIG. 20, with the secondtemplate being spaced-apart from the substrate;

FIG. 22 is a side view of the system shown in FIG. 21, with thesubstrate being positioned on the substrate chuck having a patternformed on the first and second sides thereof;

FIG. 23 is a side view of a lithographic system having a first templateopposed a second template and a substrate, the substrate having firstand second opposed sides, in a further embodiment;

FIG. 24 is a flow diagram showing a method of patterning the first andsecond opposed sides of the substrate shown in FIG. 23, in a furtherembodiment;

FIG. 25 is a side view of the system shown in FIG. 23, with thesubstrate having a material positioned on the first and second sidesthereof;

FIG. 26 is a side view of the system shown in FIG. 25, the substratebeing in a desired spatial relationship with a pin;

FIG. 27 is a side view of the system shown in FIG. 26, the substratebeing positioned on the pin;

FIG. 28 is a side view of the system shown in FIG. 27, with the secondtemplate contacting the fluid positioned on the second side of thesubstrate;

FIG. 29 is a side view of the system shown in FIG. 28, with the firsttemplate contacting the fluid positioned on the first side of thesubstrate;

FIG. 30 is a side view of the system shown in FIG. 29, with the firsttemplate being spaced-apart from the substrate; and

FIG. 31 is a side view of the system shown in FIG. 30, with the firstand second templates being spaced-apart from the substrate.

DETAILED DESCRIPTION

Referring to FIG. 1, a system 10 is shown to form a relief pattern on afirst side 12 and a second side 14 of a substrate 16. In an example,substrate 16 may be substantially absent of an alignment mark. Substrate16 may be coupled to a substrate chuck 18, with substrate chuck 18 beingany chuck including, but not limited to, vacuum and electromagnetic.Substrate chuck 18 may further comprise a cavity 19 facing substrate 16.Substrate 16 and substrate chuck 18 may be supported on a first stage 20and a second stage 22, with first stage 20 being positioned betweensubstrate chuck 18 and second stage 22. Further, first and second stages20 and 22 may be positioned on a base 23. First stage 20 may providemotion about a first axis while second stage 22 may provide motion abouta second axis, the second axis being orthogonal to the first axis, i.e.the first and second axes being the x and y axes. Exemplary stages inthe present invention are available under part number XM2000 fromNewport Corporation of Irvine, Calif. Substrate 16 further comprises athroughway 25 having an aperture 27 about first side 12 of substrate 16and an aperture 29 about second side 14 of substrate 16. However, in afurther embodiment, substrate 16 may be substantially absent ofthroughway 25.

Spaced-apart from substrate 16 is a template 24 having a mesa 26extending therefrom towards substrate 16 with a patterning surface 28thereon. Mesa 26 may also be referred to as a mold 26. However, in afurther embodiment, template 24 may be substantially absent of mold 26.Template 24 and/or mold 26 may be formed from such materials includingbut not limited to, fused-silica, quartz, silicon, organic polymers,siloxane polymers, borosilicate glass, fluorocarbon polymers, metal, andhardened sapphire. As shown, patterning surface 28 comprises featuresdefined by a plurality of spaced-apart recesses 30 and protrusions 32.However, in a further embodiment, patterning surface 28 may besubstantially smooth and/or planar. Patterning surface 28 may define anoriginal pattern that forms the basis of a pattern to be formed on firstand second sides 12 and 14 of substrate 16, described further below.Template 24 may be coupled to a template chuck 34, template chuck 34being any chuck including, but not limited to, vacuum andelectromagnetic. Further, template chuck 34 may be coupled to an imprinthead 36 to facilitate movement of template 24 and mold 26.

Referring to FIGS. 2 and 3, a top down view of template 24 isillustrated. As shown, template 24 comprises a circular shape. However,in a further embodiment, template 24 may comprise any geometric shapedesired. Further, template 24 may comprise a first region 38, a secondregion 40, and a third region 42, with the second region 40 beingpositioned between first region 38 and third region 40. Second region 40may be referred to as an active region 40. Furthermore, as shown, thirdregion 42 may be positioned at a center of template 24; however, in afurther embodiment, third region 42 may be positioned at any location oftemplate 24 desired. Mold 26, shown in FIG. 1, may be in superimpositionwith active region 40. Active region 40 and third region 42 may have aheight h₁. In an example, height h₁ may be in the range of 5-15 microns.In a further embodiment, the height of active region 40 and third region42 may differ. Furthermore, there may be a recession 44 positionedbetween active region 40 and third region 42.

Referring to FIGS. 2 and 4, third region 42 may comprise an alignmentmark 46. In an example, alignment mark 46 may be a standard universalalignment target (UAT). Alignment mark 46 may be employed to obtain adesired spatial relationship between template 24 and substrate 16, shownin FIG. 1.

Referring to FIG. 1, system 10 further comprises a fluid dispenser 48.Fluid dispenser 48 may be in fluid communication with substrate 16 so asto position a polymeric material 50 on substrate 16, described furtherbelow. As shown, fluid dispenser 48 is coupled to template chuck 34;however, in a further embodiment, fluid dispenser 48 may be coupled toany part of system 10, i.e., template 24 or imprint head 36. Further,system 10 may comprise any number of fluid dispensers and fluiddispenser 48 may comprise a plurality of dispensing units therein.Polymeric material 50 may be positioned on substrate 16 using any knowntechnique, e.g., drop dispense, spin-coating, dip coating, thin filmdeposition, thick film deposition, and the like. As shown, polymericmaterial 50 may be positioned upon substrate 16 as a plurality ofspaced-apart droplets 52.

System 10 further comprises a source 54 of energy 56 coupled to directenergy 56 along a path 58. In an example, source 54 may be anultraviolet emitting lamp coupled with either a liquid guide or anultraviolet fiber guide. An exemplary source of energy in the presentinvention is available under part number BlueWave™ 200 Spot Lamp fromDYMAX Corporation of Torrington, Conn. Imprint head 36 and first andsecond stages 20 and 22 are configured to arrange mold 26 and substrate16, respectively, to be in superimposition and disposed within path 58.Either imprint head 36, first and second stages 20 and 22, or acombination of the above, may vary a distance between mold 26 andsubstrate 16 to define a desired volume therebetween that is filled bypolymeric material 50, described further below.

System 10 further comprises an optical detection system having imagingunits 60 a and 60 b. As shown, imaging unit 60 a may be coupled to fluiddispenser 48; however, in a further embodiment, imaging unit 60 a may becoupled to any part of system 10, i.e., template 24, template chuck 34,or imprint head 36. Furthermore, as shown, imaging unit 60 b is coupledto second stage 22; however, in a further embodiment, imaging unit 60 bmay be coupled to any part of system 10, i.e., substrate chuck 18 orfirst stage 20. Further, system 10 may comprise any number of imagingunits 60 a and 60 b. Imaging units 60 a and 60 b may be a microscope indata communication with an image processing module (not shown). In afurther embodiment, imaging units 60 a and 60 b may be a laser edgedetecting sensor.

Referring to FIGS. 1, 5, and 6, imaging units 60 a and 60 b may beemployed to detect substrate 16 and mold 26, respectively. Morespecifically, imaging units may detect an edge 62 of substrate 16. In afurther embodiment, imaging unit 60 a, now shown as imaging units 64 a,64 a′, 64 b, and 64 b′ in FIGS. 5 and 6, may be employed to determine acenter location of substrate 16, i.e. throughway 25 about the x and yaxes. More specifically, imaging units 64 a and 64 b may be lasersproducing beams 66 a and 66 b, respectively, with imaging units 64 a′and 64 b′ being intensity sensors detecting beams 66 a and 66 b,respectively. As shown, imaging units 64 a, 64 a′, 64 b, 64 b′ maydetect aperture 25. Imaging units 64 a and 64 b may be employed asoff-axis or thru-the-template. Exemplary intensity sensors employed inthe present invention are available under part number LV-H37 fromKeyence, Inc. of Woodcliff Lake, N.J.

Referring to FIGS. 1 and 7, system 10 further comprises a robot 68 forpositioning substrate 16 upon and removing substrate 16 from substratechuck 18. Robot 68 may be any handling robot known in the art. In anexample, robot 68 comprises an arm 70 coupled to a driving means 72. Arm70 further has an end effecter 73 coupled thereto to handle substrate16. In an example, end effecter 73 may be an edge-gripping or thin aircavity chuck to hold substrate 16 without contacting an area ofsubstrate 16 having polymeric material 50 positioned thereon, i.e. theactive area of substrate 16. Driving means 72 may extend or contract arm70, rotate arm 70 around its axis, move arm 70 horizontally in a circle,or provide any desired motion of arm 70. Driving means 72 may providemotion about the first and second axes mentioned above. In an example,driving means 72 may rotate about the x axes to flip substrate 16,described further below. Driving means 72 may also rotate about itsaxis. Furthermore, robot 68 may transport substrate 16 between substratechuck 18 and a substrate cassette 74. Substrate cassette 74 may comprisea plurality of substrates 16 therein.

Referring to FIG. 1, typically, polymeric material 50 may be positionedupon substrate 16 before the desired volume is defined between mold 26and substrate 16. However, polymeric material 50 may fill the volumeafter the desired volume has been obtained. After the desired volume isfilled with polymeric material 50, source 54 may produce energy 56,e.g., broadband ultraviolet radiation that causes polymeric material 50to solidify and/or cross-link conforming to a shape of first side 12 ofsubstrate 16 and patterning surface 28 of mold 26. Control of thisprocess is regulated by a processor 76 that is in data communicationwith first and second stage 20 and 22, imprint head 36, fluid dispenser48, source 54, imaging units 60 a and 60 b, and robot 68, operating on acomputer readable program stored in memory 78.

As mentioned above, system 10 may be employed to form a pattern on firstside 12 of substrate 16. However, it may be desired to form a pattern onsecond side 14 of substrate 16 such that both first and second sides 12and 14 of substrate 16 have patterns formed thereon. To that end,described below are a system and a method of forming a pattern on firstand second sides 12 and 14 of substrate 16.

Referring to FIGS. 8 and 9, in a first embodiment, a method and a systemof forming a pattern on first and second sides 12 and 14 of substrate 16are shown. As mentioned, above, at step 100, substrate 16 may bepositioned upon substrate chuck 18. More specifically, first and secondstages 20 and 22 may position substrate chuck 18 proximate to robot 68such that robot 68 may position substrate 16 upon substrate chuck 18.Robot 68 may transfer substrate 16 from substrate cassette 74 andposition substrate 16 on substrate chuck 18 such that a side of firstand second sides 12 and 14 may be positioned opposite to that ofsubstrate chuck 18. In a first example, robot 68 may position substrate16 such that first side 12 faces away from substrate chuck 18 whilesecond side 14 faces towards substrate chuck 18. In a second example,robot 68 may position substrate 16 such that second side 14 faces awayfrom substrate chuck 18 while first side 12 faces towards substratechuck 18. At step 102, imaging unit 60 a may determine a position ofsubstrate 16. More specifically, imaging unit 60 a may be employed todetermine a center location of substrate 16, as mentioned above withrespect to FIGS. 5 and 6, with respect to any part of system 10, i.e.mold 18, dispensing unit 48, or robot 68. As a result, a desired spatialrelationship of substrate 16 with respect to any part of system 10 maybe obtained.

Referring to FIGS. 8 and 10, at step 104, first and second stages 20 and22 may translate substrate 16 such that a desired position may beobtained between substrate 16 and fluid dispenser 48. As a result, fluiddispenser 48 may position polymeric fluid 50 upon first side 12 ofsubstrate 16, as mentioned above.

Referring to FIGS. 8 and 11, at step 106, a desired position may beobtained between substrate 16 and mold 26. More specifically, first andsecond stages 20 and 22 and imprint head 36 may position substrate chuck18 such that substrate 16 may be in superimposition with mold 26 andfurther polymeric material 50 fills the desired volume defined betweensubstrate 16 and mold 26. At step 108, as mentioned above, polymericmaterial 50 positioned on first side 12 of substrate 16 may besolidified and/or cross-linked conforming to first side 12 of substrate16 and a patterning surface 28 of mold 26. At step 110, mold 18 may beseparated from polymeric material 50 positioned on first side 12 ofsubstrate 16.

Referring to FIGS. 8 and 12, at step 112, analogous to that mentionedabove with respect to step 100, first and second stages 20 and 22 mayposition substrate chuck 18 proximate to robot 68. At step 114, robot 68may separate substrate 16 from substrate chuck 18 via robot 68. At step116, substrate 16 may be analyzed to determine if first and second sides12 and 14 of substrate 16 are patterned. To that end, at step 118, tothat end, were only one side of first and second sides 12 and 14 ofsubstrate 16 patterned, robot 68 may rotate arm 70 around its axis toflip substrate 16 180° with respect to mold 18 and further positionsubstrate 16 on substrate chuck 18 such that the remaining unpatternedside of first and second sides 12 and 14 of substrate 16 may bepositioned opposite to that of substrate chuck 18. In a first example,were first side 12 of substrate 16 patterned, robot 68 would positionsubstrate 16 such that first side 12 faces towards substrate chuck 18and second side 14 faces away from substrate chuck 18. In a secondexample, were second side 14 of substrate 16 patterned, robot 68 wouldposition substrate 16 such that second side 12 faces towards substratechuck 18 and first side 12 faces away from substrate chuck 18.Furthermore, polymeric material 50 patterned on a side of first andsecond sides 12 and 14 of substrate 16 may be positioned within cavity19 of substrate chuck 18 to minimize, if not prevent, damage topolymeric material 50. To that end, the remaining side of first andsecond sides 12 and 14 of substrate 16 may be patterned analogous tothat mentioned above in FIGS. 8-12, with substrate 16 having first andsecond sides 12 and 14 patterned shown in FIG. 13.

Referring to FIGS. 1 and 8, however, were both first and second sides 12and 14 of substrate 16 patterned, at step 120 substrate 16 may beunloaded from substrate chuck 18 and robot 68 may position substrate 16in substrate cassette 74. In a further embodiment, fluid dispenser 48may be positioned outside of system 10, with first and second sides 12and 14 of substrate 16 having polymeric fluid 50 positioned thereonoutside of system 10. Furthermore, it may be desired to remove polymericmaterial 50 from portions of substrate 16 in contact with robot 68and/or substrate chuck 18.

Referring to FIG. 14, a second embodiment of system 10 is described,shown as system 110. System 110 may be analogous to that as system 10described above with respect to FIGS. 1-7, however, system 110 mayfurther comprise an additional patterning surface, described furtherbelow.

To that end, system 110 further comprises a template 224 having a mold226 extending therefrom towards template 24 with a patterning surface228 thereon. Template 224 may be coupled to a template chuck 234.Template 224, mold 226, and template chuck 234 may be analogous to thatof template 24, mold 26, and template chuck 34, respectively, describedabove with respect to FIG. 1. Mold 226 may have substantially the samepatterning surface 228 as patterning surface 28 of mold 26; however, ina further embodiment, patterning surface 228 may differ from patterningsurface 28. Template 224, mold 226, and template chuck 234 may becoupled to second stage 22, with second stage 22 providing motion oftemplate 224, mold 226, and template chuck 234 about the second axis, asmentioned above with respect to FIG. 1. As a result, mold 226 may bepositioned in superimposition with mold 26 to facilitate patterning offirst and second sides 12 and 14 of substrate 16, described furtherbelow. In a further embodiment, template 224, mold 226, and templatechuck 234 may be further coupled to first stage 20.

System 110 further comprises a fluid dispenser 248, with fluid dispenser248 being analogous to fluid dispenser 48 mentioned above with respectto FIG. 1. As shown, fluid dispenser 248 is coupled to template chuck234; however, in a further embodiment, fluid dispenser 248 may becoupled to any part of system 210; i.e. template 224 or second stage 22.Furthermore, imagining unit 60 b is shown coupled to fluid dispenser248; however, in a further embodiment, imaging unit 60 b may be coupledto any part of system 110, i.e., second stage 22, template 224, ortemplate chuck 234. Control of fluid dispenser 248 may be regulated byprocessor 76 that is in data communication with fluid dispenser 248.

Referring to FIGS. 15 and 16, a second embodiment of a method and asystem of forming a pattern on first and second sides 12 and 14 ofsubstrate 16 are shown. As mentioned above, at step 300, substrate 16may be positioned upon substrate chuck 18. More specifically, first andsecond stages 20 and 22 may position substrate chuck 18 proximate torobot 68 such that robot 68 may position substrate 16 upon substratechuck 18. Robot 68 may transfer substrate 16 from substrate cassette 74and position substrate 16 on substrate chuck 18 such that a side offirst and second sides 12 and 14 may be positioned opposite to that ofsubstrate 18. Please note for simplicity of illustration, couplingbetween processor 76 and first stage 20, imaging unit 60 b, and fluiddispenser 248 is not shown.

At step 302, imaging units 60 a and 60 b may determine a position ofsubstrate 16. More specifically, imaging units 60 a and 60 b may beemployed to determine a center location of substrate 16, as mentionedabove with respect to FIGS. 5 and 6, with respect to any part of system10, i.e., molds 26 and 226, dispensing units 48 and 248, or robot 68. Asa result, a desired spatial relationship of substrate 16 with respect toany part of system 10 may be obtained, described further below.

Referring to FIGS. 15 and 17, at step 304, first and second stages 20and 22 may translate substrate 16 such that a desired position may beobtained between substrate 16 and fluid dispenser 48. As a result, fluiddispenser 48 may position polymeric fluid 50 upon first side 12 ofsubstrate 16, as mentioned above.

Referring to FIGS. 15 and 18, at step 306, a desired position may beobtained between substrate 16 and mold 26. More specifically, first andsecond stages 20 and 22 and imprint head 36 may position substrate chuck18 such that substrate 16 may be in superimposition with mold 26 andfurther polymeric material 50 positioned on first side 12 of substrate16 fills the desired volume defined between substrate 16 and mold 26. Atstep 308, as mentioned above, polymeric material 50 positioned on firstside 12 of substrate 16 may be solidified and/or cross-linked conformingto first side 12 of substrate 16 and patterning surface 28 of mold 26.At step 310, substrate 16 may be separated from substrate chuck 18 suchthat substrate 16 is coupled to mold 26.

Referring to FIGS. 15 and 19, at step 312, first stage 20, or in afurther embodiment, first and second stages 20 and 22, may translatefluid dispenser 248 such that a desired position may be obtained betweensubstrate 16 and fluid dispenser 248. As a result, fluid dispenser 248may position polymeric fluid 50 upon second side 14 of substrate 16,analogous to that mentioned above with respect to first side 12 ofsubstrate 16 shown in FIG. 17.

Referring to FIGS. 15 and 20, at step 314, a desired position may beobtained between substrate 16 and mold 226. More specifically, secondstage 22, or in a further embodiment, first and second stages 20 and 22,and imprint head 26 may position mold 226 to be in superimposition withsubstrate 16 with polymeric material 50 positioned on second side 14 ofsubstrate 16 filling the desired volume defined between substrate 16 andmold 226. At step 316, polymeric material 50 positioned on second side14 of substrate 16 may be solidified and/or cross-linked conforming tosecond side 14 of substrate 16 and patterning surface 228 of mold 226.In a further embodiment, step 308, mentioned above, may be omitted wheresubstrate 16 substantially transparent to the actinic radiationmentioned above such that material 50 positioned on first and secondsides 12 and 14 of substrate 16 may be solidified and/or cross-linkedconcurrently.

Referring to FIGS. 15 and 21, at step 318, mold 226 may be separatedfrom polymeric material 50 positioned on second side 14 of substrate 16such that substrate 16 remains coupled to mold 26. To facilitateseparation of mold 226 from polymeric material 50, mold 226 may be bowedtowards substrate 16 while concurrently imprint head 36 provides motionof mold 26 in a direction away from mold 226.

Referring to FIGS. 15 and 22, at step 320, first and second stage 20 and22 and imprint head 36 may position substrate chuck 18 such thatsubstrate chuck 18 may be in superimposition with substrate 16. At step322, mold 26 may be separated from polymeric material 50 positioned onfirst side 12 of substrate 16 such that substrate 16 may be positionedupon substrate chuck 18. To facilitate separation of mold 26 frompolymeric material 50, mold 26 may be bowed towards substrate 16 whileconcurrently imprint head 36 provides motion of mold 26 in a directionaway from substrate 16. Polymeric material 50 positioned on second side14 of substrate 16 may be positioned within cavity 19 of substrate chuck18 to minimize, if not prevent, damage to polymeric material 50. At step324, substrate 16 may be unloaded from substrate chuck 18 and robot 68may position substrate 16 in substrate cassette 74.

In a further embodiment, fluid dispensers 48 and 248 may be positionedoutside of system 110, with first and second sides 12 and 14 ofsubstrate 16 having polymeric fluid 50 positioned thereon outside ofsystem 110. Furthermore, it may be desired to remove polymeric material50 from portions of substrate 16 in contact with robot 68 and/orsubstrate chuck 18.

Referring to FIG. 23, a third embodiment of system 10 is described,shown as system 210. System 210 may be analogous to that as system 10described above with respect to FIGS. 1-7, however, system 210 mayfurther comprise an additional patterning surface and a pin 80 to holdsubstrate 16, described further below.

System 210 further comprises a template 324 having a mold 326 extendingtherefrom towards template 24. Template 324 may be coupled to a templatechuck 334. Template 324, mold 326, and template chuck 334 may beanalogous to that of template 24, mold 26, and template chuck 34,respectively, described above with respect to FIG. 1. Mold 326 may havesubstantially the same patterning surface 328 as patterning surface 28of mold 26; however, in a further embodiment, pattering surface 328 maydiffer from patterning surface 28. In a further embodiment, templatechuck 324 may be a spherical chucking unit having a curvature in therange of 2 microns to 100 microns over an area of template chuck 324 insuperimposition with mold 326. Pin 80 may provide motion of template 324and mold 326 in the first axis and second axis, as mentioned above withrespect to FIG. 1. Further pin 80 may provide motion along a third axisorthogonal to the first and second axis, i.e. along the x axis. In anexample, pin 80 may provide motion about the x and y axis ofapproximately 50-200 microns and along the z axis of approximately 2millimeters.

System 210 further comprises a fluid dispenser 348, with fluid dispenser348 being analogous to fluid dispenser 48 mentioned above with respectto FIG. 1. Fluid dispenser 348 and imaging unit 60 b are shown coupledto base 23; however, fluid dispenser 348 and imaging unit 60 b may becoupled to any part of system 210. Control of fluid dispenser 348 may beregulated by processor 76 that is in data communication with fluiddispenser 348.

Referring to FIGS. 24 and 25, a third embodiment of a method and asystem of forming a pattern on first and second sides 12 and 14 ofsubstrate 16 are shown. At step 400, robot 68 may retrieve substrate 16from substrate cassette 74 with robot 68 holding substrate 16. At step402, robot 68 may position substrate 16 such that a desired spatialrelationship between substrate 16 and fluid dispensers 48 and 348 may beobtained to position polymeric fluid upon substrate 16. Morespecifically, fluid dispenser 48 may position polymeric fluid 50 onfirst side 12 of substrate 16 and fluid dispenser 348 may positionpolymeric fluid 50 on second side 14 of substrate 16. In a furtherembodiment, fluid dispensers 48 and 348 may be positioned outside ofsystem 210, with first and second sides 12 and 14 of substrate 16 havingpolymeric fluid 50 positioned thereon outside of system 210. At step404, a distance between mold 26 and mold 326 may be increased such thatsubstrate 16 may be positioned between mold 26 and mold 326. Please notefor simplicity of illustration, coupling between processor 76 andimaging unit 60 b, pin 80, and fluid dispenser 348 is not shown.

Referring to FIGS. 24 and 26, at step 406, robot 68 may translatesubstrate 16 and pin 80 may translate such that a desired spatialrelationship between substrate 16 and pin 80 may be obtained. As aresult, substrate 16 may be centered with respect to pin 80. Morespecifically, throughway 25 may be in superimposition with pin 80.However, in a further embodiment, any desired spatial relationshipbetween substrate 16 and pin 80 may be obtained.

Referring to FIGS. 24 and 27, at step 408, pin 80 may translate alongthe z axis such that substrate 16 may be positioned upon pin 80. At step410, robot 68 may be retracted from holding substrate 16. Morespecifically, arm 70 of robot 68 may be retracted such that end effecter73, shown in FIG. 7, is not coupled to substrate 16. At step 412,imaging unit 60 a may determine a position of substrate 16. Morespecifically, imaging unit 60 a may be employed to determine a centerlocation of substrate 16, as mentioned above with respect to FIGS. 5 and6, with respect to any part of system 10, i.e., mold 26, mold 326, orrobot 68. As a result, a desired spatial relationship of substrate 16with respect to any part of system 10 may be obtained, described furtherbelow.

Referring to FIGS. 24 and 28, at step 414, a desired position may beobtained between substrate 16 and mold 326. More specifically, pin 80and chuck 334 may position substrate 16 and mold 326 such that substrate16 may be in superimposition with mold 326 and further polymericmaterial 50 positioned on second side 14 of substrate 16 fills thedesired volume defined between substrate 16 and mold 326.

Referring to FIGS. 24 and 29, at step 416, a desired position may beobtained between substrate 16 and mold 26. More specifically, pin 80 andimprint head 36 may position substrate 16 and mold 26 such thatsubstrate 16 may be in superimposition with mold 26 and furtherpolymeric material 50 positioned on first side 12 of substrate 16 fillsthe desired volume defined between substrate 16 and mold 26. At step418, as mentioned above, polymeric material 50 positioned on first side12 of substrate 16 may be solidified and/or cross-linked conforming tofirst side 12 of substrate 16 and patterning surface 28 of mold 26 andpolymeric material 50 positioned on second side 14 of substrate 16 maybe solidified and/or cross-linked conforming to second side 14 ofsubstrate 16 and patterning surface 328 of mold 326.

Referring to FIGS. 24 and 30, at step 420, mold 26 may be separated frompolymeric material 50 positioned on first side 12 of substrate 16.Furthermore, it may be desired to remove polymeric material 50 fromportions of substrate 16 in contact with robot 68 and/or pin 80.

Referring to FIGS. 24 and 31, at step 422, robot 68 may retrievesubstrate 16 such that end effecter 73, shown in FIG. 7, of arm 70 holdssubstrate 16. At step 424, mold 326 may be separated from polymericmaterial 50 positioned on second side 14 of substrate 16 such thatsubstrate 16 is coupled to robot 68. At step 426, substrate 16 may beunloaded from substrate chuck 18 and robot 68 may position substrate 16in substrate cassette 74.

The embodiments of the present invention described above are exemplary.Many changes and modifications may be made to the disclosure recitedabove, while remaining within the scope of the invention. Therefore, thescope of the invention should not be limited by the above description,but instead should be determined with reference to the appended claimsalong with their full scope of equivalents.

1. A method for patterning a substrate with a mold assembly, saidsubstrate having first and second opposed sides, said method comprisingthe steps of: obtaining a first spatial relationship between saidsubstrate and said mold assembly such that said first side of saidsubstrate is in superimposition with said mold assembly, said moldassembly and said first side of said substrate having a materialpositioned therebetween; forming a pattern in said material on saidfirst side of said substrate with said mold assembly, defining a firstpatterned layer; obtaining a second spatial relationship, differing fromsaid first spatial relationship, between said substrate and said moldassembly such that said second side of said substrate is insuperimposition with said mold assembly, with said mold assembly andsaid second side of said substrate having a material positionedtherebetween; and forming a pattern in said material on said second sideof said substrate with said mold assembly, defining a second patternedlayer.
 2. The method as recited in claim 1 wherein the step of obtainingsaid second spatial relationship further comprises a step of flippingsaid substrate.
 3. The method as recited in claim 1 wherein the step ofobtaining said second spatial relationship further comprises a step offlipping said substrate 180 degrees with respect to said mold assembly.4. A method for patterning a substrate, said substrate having first andsecond opposed sides, said method comprising the steps of: positioning amaterial on said first side of said substrate; obtaining a first spatialrelationship between said substrate and a first mold assembly such thatsaid first side of substrate is in superimposition with said first moldassembly; forming a pattern in said material on said first side on saidsubstrate with said first mold assembly, defining a first patternedlayer; positioning a material on said second side of said substrate;obtaining a second spatial relationship, differing from said firstspatial relationship, between said substrate and said second moldassembly such that said second side of said substrate is insuperimposition with said second mold assembly; and forming a pattern insaid material on said second side of said substrate with said secondmold assembly, defining a second patterned layer.
 5. The method asrecited in claim 4 wherein the step of forming said pattern in saidmaterial on said first side of said substrate further comprises a stepof coupling said substrate to said first mold assembly such that saidmaterial may be positioned on said second side of said substrate.
 6. Asystem for patterning a substrate having first and second opposed sides,said system comprising: a mold assembly; and a robot coupled to saidsubstrate to alternatively place said substrate in first and secondpositions with respect to said mold assembly such that said moldassembly may contact a material positioned on said first opposed side ofsaid substrate, defining a first patterned layer, and further contact amaterial positioned on said second opposed side of said substrate,defining a second patterned layer.
 7. The system as recited in claim 6further including first and second opposed fluid dispensers, said firstfluid dispenser positioning said material on said first side of saidsubstrate and said second fluid dispenser positioning said material onsaid second side of said substrate.
 8. The system as recited in claim 6further including an optical detection system to determine a spatialrelationship between said mold assembly and said substrate.
 9. Thesystem as recited in claim 6 wherein said robot further flips saidsubstrate 180 degrees with respect to said mold assembly.
 10. A systemfor patterning a substrate having first and second opposed sides, saidsystem comprising: a first mold assembly; a second mold assemblypositioned opposite to said first mold assembly; and a translation stagealternatively placing said substrate in first and second positions withrespect to said first and second mold assemblies such that in said firstposition said first mold assembly contacts a material positioned on saidfirst side of said substrate and in said second position said secondmold assembly contacts a material positioned on said second side of saidsubstrate.
 11. The system as recited in claim 10 further including firstand second opposed fluid dispensers, said first fluid dispenserpositioning said material on said first side of said substrate and saidsecond fluid dispenser positioning said material on said second side ofsaid substrate.
 12. The system as recited in claim 10 further includingan optical detection system to determine a spatial relationship betweensaid mold assembly and said substrate.
 13. The system as recited inclaim 10 wherein said robot further flips said substrate 180 degreeswith respect to said mold assembly.